Field of the Invention
The present invention relates to laundry treatment appliances or machines. In more detail, the present invention refers to appliances for drying laundry (laundry drying machines), both for domestic and professional use, and particularly to a laundry washing machine also having a laundry drying functionality (laundry washing/drying machines).
Background
Laundry drying and laundry washing/drying machines—which will be referred to simply as laundry machines in the following—typically comprise a casing substantially parallelepiped—shaped forming a machine cabinet. The cabinet accommodates therein a laundry treating chamber, comprising a drum, generally rotatable, apt to contain the laundry to be dried. In laundry washing/drying machines, the drum is rotatably contained in a washing tub, adapted to contain the laundry washing liquid when the machine is operated in laundry washing mode. A front panel of the cabinet has a loading opening to access the treating chamber, for loading/unloading the laundry, and a door is hinged to the cabinet front panel for closing the loading opening, particularly during the laundry machine operation.
The cabinet also accommodates the electrical, electronic, electro-mechanical, mechanical, and hydraulic components necessary for the operation of the laundry machine. Particularly, laundry machines features an air circuit (comprising, for example, fans, air ducts, a moisture condensing unit, a heating unit, etc.) adapted to heat air, blow it into the drum where it removes moisture from the laundry, suck out from the drum the moisturized air, de-moisturize the air and reiterate such actions thereby performing a laundry drying cycle.
In a known type of laundry machines, also referred to as “condenser dryer”, the drying air flow is typically caused to pass through the drum, exiting therefrom from the drum front access opening, then the moisture-laden drying air flow passes through a moisture condensing system, where the humid air is at least partially dehydrated, dried, and the dried drying air flow is heated up by means of a heating arrangement, like an electrical resistance; the heated drying air flow then passes again through the drum, and repeats the cycle.
The condensing system may be an air-air heat exchanger, exploiting air taken in from the outside.
Other known laundry machines exploit a heat pump to dehydrate the drying air flow. In these laundry machines, the function of the heating arrangement may be performed by the heat pump itself, and the electrical resistance may thus not be provided for.
For some household appliance manufacturers, it might be interesting to exploit the already existing design of a laundry washing machine for producing and offering to the customers a laundry washer/dryer. The addition of those components and parts, that are necessary for the laundry drying function, should have as low as possible impact on the already existing design; in particular, the additional components should be housed within the already existing laundry washing machine cabinet.
EP 2270274 discloses a top adapted to match and close from above a cabinet of a laundry drying appliance, the top being formed as a ready-to-mount part ready to be mounted to the cabinet and forming a moisture condensing module for dehydrating drying air used to dry laundry within a drying drum of the laundry drying appliance. The top has a drying air inlet, a drying air outlet, fluid passageways defined thereinside from said drying air inlet to said drying air outlet for the passage of the drying air to be dehydrated and moisture condensing means arranged inside said fluid passageways.
The top disclosed in EP 2270274, once assembled, forms a unit that is ready to be mounted to the machine cabinet, simply by placing the top in the correct alignment, so that the drying air inlet opening and the drying air outlet opening match an outlet of a drying air return duct and, respectively, an intake of a drying air circulation fan, both of which are fixed, rigidly connected to the machine cabinet. In such a way, the outlet of the return air duct and the air intake of the air circulation fan act as automatic positioning and centering means for the top, simplifying the mounting thereof: the operation of mounting of the top onto the cabinet simply consists in laying the top on the cabinet properly positioning it with the help of the self-centering action achieved by the matching of the openings provided in the top with the outlet and air intake; in this way, all the necessary connections for the drying air circulation circuit are completed, and there is no necessity to perform any additional connection.
The Applicant believes that while the top disclosed in EP 2270274 is advantageous under several respects, has some drawbacks.
In particular, a disadvantage of the top disclosed in EP 2270274 consists in that possible leakage of drying air (process air) may occur after the top has been assembled to the machine cabinet. In fact, the positioning of the top is the only occasion for coupling the drying air circuit portion located within the top with the remaining drying air circuit portion placed under the top, i.e. in a lower volume of the machine cabinet. Once the top is assembled to the cabinet, the drying conduit cannot be reached anymore. Since a leakage of process air reduces the performance of a drying process, it would be desirable to improve the fixation of the drying air circuit portions and its verification by an assembler, to avoid any risk of drying air leakage during a drying process.